seo – How should i get my subdirectories indexed?

I have a main website which is mainly used for targeting one country. We recently started creating sub directories for targeting other countries i.e,, etc., We have replicated the same and created subdirectories i.e, content and design are same. I have put canonical url for subdirectories as as that is the primary domain.
Now, after optimizing sub directory pages based on country wise, i have changed certain sub directories canonical url as – My subdirectories are not getting crawled or indexed. In search console, it shows me the error – “Duplicate, submitted URL not selected as canonical”
I have changed canonical urls but its been a month, the pages are not still not shown on SERP. Kindly suggest me what should i do to get my pages crawled.